Microcarriers have been employed in cell culture for the purpose of providing high yields of attachment-dependent cells. Microcarriers are typically stirred or agitated in cell culture media and provide a very large attachment and growth surface area to volume ratio relative to more traditional culture equipment.
Most currently available microcarriers provide for non-specific attachment of cells to the carriers for cell growth. While useful, such microcarriers do not allow for biospecific cell adhesion and thus do not readily allow for tailoring of characteristics of the cultured cells. For example, due to non-specific interactions it may be difficult to maintain cells, such as stem cells, in a particular state of differentiation or to direct cells to differentiate in a particular manner.
Some currently available microcarriers provide for bio-specific adhesion, but employ animal derived coating such as collagen or gelatin. Such animal derived coatings can expose the cells to potentially harmful viruses or other infectious agents which could be transferred to patients if the cells are used for a therapeutic purpose. In addition, such viruses or other infectious agents may compromise general culture and maintenance of the cultured cells. Further, such biological products tend to be vulnerable to batch variation and limited shelf-life.